Emesis is a well-known and frequent side-effect of cancer chemotherapeutic agents, such as cisplatin. It causes serious problems in cancer chemotherapy, and in some patients emesis is so severe that therapy must be discontinued. Anti-emetic agents are therefore often administered in order to alleviate this side-effect of the cancer chemotherapeutic agent. The anti-emetic agents employed are usually benzamide derivatives, such as metoclopramide, which have dopamine antagonist activity. In view of their dopamine antagonist activity benzamide derivatives such as metoclopramide themselves exhibit serious and undesirable side-effects, such as extra-pyramidal effects, i.e. tardive dyskinesia, acute dystonia, akathisia and tremor. Other anti-emetic drugs include 5-HT3 antagonists, e.g., ondansetron; corticosteroids, e.g., dexamethasone; and NK1 antagonists, e.g., aprepitant. These treatments fail to adequately address the needs of the patient.
In view of the above, an effective treatment for emesis that minimizes or eliminates one or more of the side effects of therapies that are currently available is highly desirable.